Thrombin Time (TT) |
EPIC Test Name
THROMBIN TIMEEPIC Code
LAB324Specimen Requirements
Plasma | |
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Minimum Volume: | 2.7 mL |
Collection: | Collect using standard laboratory procedures. Tubes must be full to obtain proper blood to anticoagulant ratio or the specimen will be rejected. |
Transport: | Specimens scheduled to arrive in lab in less than 4 hours can be sent at room temperature. Specimens arriving more than 4 hours must be platelet poor specimens and need to be frozen before transport. Place in an insulated container filled with dry ice to ensure that the specimen does not thaw. |
Stability: | Room temp: 4 hours Frozen: 2 weeks at -20 C 6 months at -70 C. |
Container: | Light-blue top (3.2% sodium citrate) |
Processing/Storage: | Specimens that cannot reach the lab within the time frame should be double spun at 2500 g for 15 minutes to obtain platelet poor plasma. 0.5mL aliquots should be frozen in plastic at -20 degrees C. |
Rejection Causes: | Clotted Insufficent Sample Volume |
Methods
Automated clotting assayTurnaround Time
Specimen | Turnaround Time |
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Plasma | Stat : 45 minutes Routine: 4 hours |
Reference Ranges
Automated clotting assay
All Range | Unit |
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15.0-19.0 seconds | second |
Clinical Indications
Useful in the workup of prolonged PTT and PT. Prolonged TT suggests low fibrinogen level or the presence of a thrombin inhibitor (dabigatran, bivalirudin, argatroban, unfractionated heparin). TT is especially prolonged by UH. Elevated fibrin degradation products are also inhibitors of thrombin and contribute to prolonged TT in DIC. Deficiency of other coagulation factors, warfarin, Xa inhibitors, and lupus anticoagulants do not influence TT.Performed
Lab |
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Hematology - Downtown |